Plasma display panels (PDP) can be divided into two types, the direct current (DC) type and the alternating current (AC) type, according to their electrical driving mode. In FIG. 1, which illustrates a conventional AC-type PDP, glass plates 11, 12 undergo several manufacturing steps in which many functional layers are formed thereon and are then combined together by sealing the periphery of the glass plates 11, 12. A mixed gas with a predetermined ratio is then introduced into the discharge units between the glass plates 11, 12.
In FIG. 1, a plurality of parallel transparent electrodes 111 and bus electrodes 112, a dielectric layer 113 and a protective layer 114 are sequentially formed on the glass plate 11, hereinafter referred to as front plate 11. Similarly, a plurality of parallel address electrodes 121, a plurality of parallel barrier ribs 122, a fluorescencer 123 and a dielectric layer 124 are formed on the glass plate 12, hereinafter referred to as back plate 12. One transparent electrode 111 on the front plate 11 and one address electrode 121 on the back plate 12, transparent electrode 111 and address electrode 121 being perpendicularly crossed, compose a discharge unit. When a voltage is applied to a specific discharge unit, gas discharge occurs at the discharge unit between the dielectric layers 113 and 124 to induce emission of a colored visible light from the fluorescencer 123.
FIG. 2 is a schematic, cross-sectional view corresponding to FIG. 1. In a conventional AC-type PDP 10, referring to FIGS. 1 and 2 simultaneously, a plurality of parallel-arranged transparent electrodes 111 are formed on the front plate 11. Each of the transparent electrodes 111 correspondingly has a bus electrode 112 to reduce linear resistance of the transparent electrodes 111. In one discharge unit 13, a three-electrode structure, including an X electrode and an Y electrode of the transparent electrode 111 on the front plate 11 and an address electrode 121 on the back plate 12, is generally employed. When a voltage is applied to the above three electrodes of a specific discharge unit 13 to induce discharge, the mixed gas in the discharge unit 13 emits ultraviolet (UV) rays to light the fluorescencer 123 inside the discharge unit 13. The fluorescencer 123 then emits a visible light, such as a red (R), green (G) or blue (B) light. An image is thus produced by scanning the discharge unit array.
In the conventional AC-type PDP 10, the barrier ribs 122 are arranged in parallel strips on the back plate 12. The address electrode 121 between two adjacent barrier ribs 122 is disposed inside the dielectric layer 124. In the structure, the fluorescencer 123 can only be coated on the sidewalls of the barrier ribs 122 and the top surface of the dielectric layer 124, so that only three planes are utilized. In each discharge unit 13, the fluorescencer 123 is coated on a small surface area, so that a low luminescence efficiency is obtained in the conventional PDP 10.
Since an erroneous discharge may occur in a non-discharge unit 13a, illustrated in FIG. 3, of the conventional AC-type PDP 10, the distance d between two adjacent discharge units 13 must be increased to prevent the same. Although a larger non-discharge unit 13a prevents erroneous discharge, discharge units 13 are then relatively contracted, i.e. have a reduced opening ratio, and luminescence efficiency is thus decreased. Conversely, a smaller non-discharge unit 13a provides larger discharge units 13, but erroneous discharge then readily occurs, so that neighboring discharge units 13 are affected during operation.
In addition, no isolation is provided between the discharge region A and non-discharge region B and erroneous discharge thus readily occurs in the non-discharge region B. A conventional method for solving the erroneous discharge issue in non-discharge region B is to perform an additional treatment of forming black strips to shade a light produced in the non-discharge region B. The contrast of the conventional PDP 10 is therefore increased, but further manufacture cost is incurred.
To solve the foregoing described problems, a discharge region having sealed latticed structure has been provided as shown in FIG. 4. In accordance with the structure, barrier ribs are used to isolate the discharge region A and the non-discharge region B. The discharge region A is a closed space according to this structure. Therefore, the problem of erroneous discharge occurring in the non-discharge region B is solved. On the other hand, the fluorescencer can be coated on the five planes of each discharge unit, i.e. front, back, left, right and bottom planes, thereby improving luminescence efficiency by increasing the fluorescencer coating area. The vacuuming and refilling gas steps are performed between the discharge region A and non-discharge region B after the front and back glass plates of the PDP are adhered to each other. However, the flat surface of the front plate results in the discharge region being closed. The closed discharge region results in greater difficulties when performing the vacuuming and refilling gas steps. Even if the two steps are finished, the process time of the two steps increases due to the structure.